28 PINNA. 



exterior by artificial means, Mytihcs harhatns 

 is not unfrequent on our shores ; the colour is 

 brown, and the shell is shaggy. Number of 

 species, forty-nine. 



^' Our last bivalve genus is Pinna. The generic 

 characters — shell bivalve, brittle, erect, gaping 

 at one end, throwing out a byssus ; hinge without 

 teeth. (Plate 6.) 



'^ The Pinna race are found plentifully in the 

 Mediterranean, the Indian, American, and At- 

 lantic oceans : the British seas afford three species. 

 The genus is noted for producing a fine byssus, 

 that is manfactured in Italy into various articles, 

 as gloves. The animal is sometimes used as an 

 article of food. 



*' An ancient writer asserts that the Pinna is 

 attended by a crab, that finds a habitation in its 

 shell, and repays the favour by giving notice, by 

 a gentle nip, when a fish comes within reach ; 

 the Pinna opens the valves of the shell, and se- 

 cures the prey, which serves for the food of both. 

 Now, Charles, you know the whole sense of the 

 quotation— 



'* ' The anchored pinna and his cancer friend.' " 



